Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages


home | help
I4BIPR(4)		 BSD Kernel Interfaces Manual		     I4BIPR(4)

     i4bipr -- isdn4bsd	IP over	ISDN B-channel network driver

     device "i4bipr" [count]

     The i4bipr	driver interfaces the IP subsystem of the operating system
     with the isdn4bsd package so that transport of IP packets over an ISDN
     link is possible.

     The driver	just packs IP packets without anything appended	or prepended
     into raw HDLC packets on the B channel and	transfers them to a remote
     site.  IP packets received	from the remote	site are queued	into the local
     IP	protocol stack.

     The format	of the resulting packet	on the B channel is:

	   (HDLC opening flag) (IP-packet) (CRC) (HDLC closing flag)

     In	the case where an IP packet for	a remote site arrives in the driver
     and no connection has been	established yet, the driver communicates with
     the isdnd(8) daemon to establish a	connection.

     The driver	has support for	interfacing to the bpf(4) subsystem for	using
     tcpdump(1)	with the ipr interfaces.

     The driver	optionally (when compiled with the IPR_VJ option) provides Van
     Jacobsen header compression, under	control	of the link0 and link1 options
     to	ifconfig(8):

	   link0	    Apply VJ compression to outgoing packets on	this
			    interface, and assume that incoming	packets	re-
			    quire decompression.
	   link1	    Check incoming packets for Van Jacobsen compres-
			    sion; if they appear to be compressed, automati-
			    cally set link0.

     The default values	are on for link1 and off for link0.

     tcpdump(1), bpf(4), isdnd.rc(5), isdnd(8)

     The i4bipr	device driver and this manpage were written by Hellmuth
     Michaelis <>.

BSD				 July 28, 2002				   BSD


Want to link to this manual page? Use this URL:

home | help